Odd oxygen
= Odd oxygen
{title2=$O_x=\mathrm O+\mathrm O_3$}
A chemical-family bookkeeping variable in a simple stratospheric model. Interconversion of atomic oxygen and ozone preserves this count, while $\mathrm O+\mathrm O_3\to2\mathrm O_2$ removes two units. The definition must be extended consistently when including additional reservoirs or excited atomic states.